Teaching:TUW - UE InfoVis WS 2005/06 - Gruppe G4 - Aufgabe 2

Poor Graphic

SlicerDicer's Sales Compared to Other Products (click on image for larger version)

Analysis of the Graphic

Here we have got an example for a low data-ink ratio. The data-ink ratio is the proportion of the ink that is used to present actual data, without redundancy, compared to the total amount of ink used in the entire display. The goal is to receive the highest possible data-ink ratio (a value close to 1.0 or 100%).
The data-ink ratio is defined as the percentage: (100*data-ink)/(total ink used on the graph) [Tufte, 1983]
First off all we have to distinguish between data-ink and non-data-ink:

data-ink is the essential non-erasable ink used to present the data
non-data-ink is the redundant ink used to ellaborate or decorate the graph [Hunt, 1997]

To enhance the data-ink ratio we have to

remove unnecessary non-data-ink
regularize the remaining non-data-ink and
emphasize the most important data-ink. [Few, 2004]

How much of the ink in our example is completely unnecessary and could be removed?

the border around the legend
the border around the plot area
the grid
the black borders around the bars, because they have no value
the repitition of the dollar-sign for each revenue value is redundant. It would be better to replace them by simply adding the label "U.S. $" to the vertical axis.

Correction of the Graphic

Modifications:

used a line graph instead of a bar graph
used visual attributes to highlight certain data.
exchanged the gridlines with a grid consisting of a group of slightly coloured fields
changed the step size of the values on the y-axis.
changed the style and format of the legend in two different ways.
changed the colours of the graphs using the full colour-spectrum.
changed the text to proper upper- and lowercase.
changed all text to horizontal alignment.
removed redundant text from the graphic.
removed all unnecessary lines.
removed unnecessary data.
added the source and the author of the graphic.

Updated Graphics:

SlicerDicer's Sales Compared to Other Products (Version 1)

SlicerDicer's Sales Compared to Other Products (Version 2)

References:

[Few, 2004] Stephen Few, Elegance through simplicity, Faculty of Information and Media Studies at the University of Western Ontario, Last updated: October 16, 2004, Retrieved at: October 30, 2005, http://www.intelligententerprise.com/showArticle.jhtml;jsessionid=N2ATDQWY5VYKSQSNDBGCKHSCJUMEKJVN?articleID=49400920
[Tufte, 1983] Tufte, Edward. The Visual Display of Quantitative Information. Graphics Press, Cheshire, 1983.
[Hunt, 1997] Neville Hunt, Data Ink. Created at: 1997. Retrieved at: October 30, 2005. http://home.ched.coventry.ac.uk/Volume/contents.htm.